1. Technical Field
The present invention relates to a device and a method for relaying packets.
2. Description of the Related Art
Link aggregation based on the IEEE 802.3ad standard is a known redundant configuration for networks. By link aggregation, it is possible to aggregate a number of physical ports and treat them as a single virtual logical port. A method for distributing the communication load, by using a function to convert information (e.g. the header of a frame being transmitted) into an output value, and based on the output value, selecting a transmission cue corresponding to one of several links is also known (see Japanese Patent Published Application No. 2005-252758A).
The use of bandwidth control to control data transfer speed in a network relay device is also known. Bandwidth control can be implemented through various known methods for controlling data transfer speed, for example, control by limiting the data transfer speed ceiling, or control to ensure a lower limit for data transfer speed. In such instances, a known technique for attaining a faster packet relay process involves providing the network relay device with a multiplicity of bandwidth controllers, with each bandwidth controller performing bandwidth control in relation to a different physical port. Another known related technology is disclosed in Japanese Patent Published Application 2006-5437A.
Where a logical port is configured spanning multiple bandwidth controllers by link aggregation, bandwidth control in relation to the logical port will be carried out in an uncoordinated manner by the multiple bandwidth controllers. A result is that in some instances, the bandwidth of the logical port as a whole cannot be appropriately controlled.